Commercial man-made polymeric textile fibers and filaments may be manufactured continuously from the raw materials to the finished fiber product. However, it is difficult to synchronize polymerization and fiber spinning and processing. Moreover, many fiber producers do not have the polymerization capability; and of those who have in-house polymerization capability it is sometimes physically remote from fiber spinning and process facilities. For these reasons it is quite common to prepare an intermediate polymeric granule or flake in which form the polymer can be easily handled, sold, stored, shipped, and then melted for further processing.
The granulation of hard brittle material, particularly polymeric material such as polyester polymer, is accomplished commercially only with the finest and hardest of cutter blades under ideal conditions, preferably utilizing the cooling effect of an underwater operation. Flake cutting, according to methods and apparatus described in such patents as U.S. Pat. Nos. 2,850,764, 3,277,519, and 3,600,745, is well known in the art. Flake cutting machines according to these methods and apparatus, when placed in continuous use, require frequent shutting down and resharpening or replacement of cutters. Production time is lost, and replacement cutters are expensive. Since wear and tear on cutter blades is very high, any apparatus by which cutter blade life can be substantially increased or blade wear can be substantially reduced, would be a meritorious advance in the art. Moreover there is a well recognized and long felt need for increased cutter blade life in these machines.